The pharmacotherapy of alcoholism is receiving increasing attention. Although a number of studies have recently been conducted on the efficacy of various medications in this disorder, the one that appears to show the greatest clinical promise is the opiate antagonist, naltrexone. A number of studies in animals suggest that opiate antagonists block various alcohol induced effects including the free choice self-administration of alcohol. Other studies suggest that opiates and alcohol may interact with the meso-limbic dopamine neurotransmitter system which may be involved with the reinforcing, sensitizing, and stress reducing effects of these substances. This would suggest that certain patient characteristics, which might be the result of abnormalities in these systems, may be predictive of better responses to opiate antagonist medications. Although our group has not conducted studies with naltrexone in alcohol dependent individuals, we have conducted studies with naltrexone in other populations and have conducted pharmacologic and psychotherapeutic studies in alcoholism. The primary goal of this proposal is to examine the efficacy of naltrexone, combined with cognitive-behavioral therapy, in the treatment of alcohol dependent outpatients. A secondary goal of this proposal is to test the hypothesis that certain patient characteristics, measured prior to the start of the study, will be predictive of response to naltrexone and cognitive-behavioral therapy. The proposed study will be a randomized, placebo controlled, trial in 160 alcohol dependent, relatively treatment naive outpatients, who will have had difficulty cutting down or controlling their drinking. After 5 days. of sobriety, patients will be assessed with psychological, cognitive, and a stress reduction procedure (alcohol expectancy stress response dampening). These assessments will form the data base for our exploratory patient matching hypotheses. The patients will then be randomly assigned to receive naltrexone 50 mg. per day or matching placebo. They will be treated with the study drug and weekly structured cognitive-behavioral therapy for twelve weeks. They will be assessed weekly for alcohol consumption and craving, and monthly for psychosocial status, mood changes, cognitive functioning, and biologic markers of alcohol consumption. Patients who complete the study will be contacted one month and three months after the end of the treatment phase and evaluated for alcohol consumption, relapse, and psychosocial status. State-of-the-art procedures for diagnosis, measurement of alcohol consumption, biologic markers of abusive drinking, mediation compliance, and quality control for standardization of cognitive behavioral therapeutic techniques will be utilized to evaluate the efficacy of naltrexone compared to placebo.